Add integration scaffolding script (#26777)

* Add integration scaffolding script

* Make easier to develop

* Update py.test -> pytest

script/scaffold/error.py

@@ -0,0 +1,10 @@
+"""Errors for scaffolding."""
+
+
+class ExitApp(Exception):
+    """Exception to indicate app should exit."""
+
+    def __init__(self, reason, exit_code):
+        """Initialize the exit app exception."""
+        self.reason = reason
+        self.exit_code = exit_code